I seem to choose a new candidate for this title every few weeks. I usually find beautiful photos on photography blogs such as this on (the colors! SQUEE!) and this one (by a fellow Chesterton fan, as a bonus). But the other day I stumbled across this photo on Google images, and thought it was simply breathtaking.
I don't know why I love it so much... perhaps because of how quiet it is in its beauty... or perhaps because the girl's hair looks a bit like mine (only prettier).